Power lift



Feb. 23, 1932. F. w. PERRY ET AL 1,846,436

POWER LIFT Filed Aug. 6, 1928 2 Sheets-Sheet l Dam (amp/awed 19/) Sappjr Patent ed Feb. 23, 1932 UNITED STA S PATENT OFFICE IJFBANCIS W. PERRY AND EDWIN L. WIEGAND, PITTSBURGH, PENNSYLVANIL, LB- bIEl-NOBS, BY KEBNE ASSIGNMENTS, T0 EDWIN Ir- WIEGAND, OF PITTSBURGH, PENN- ESYL'VANIA rowan 111m Application filed August 8, 1928. Serial No. $397,700.

This invention relates to an improved power lift, and more particularly to an apparatus of this class that is especially suitable for use in or about service stations, garages,

s and like places, for lifting automotive vehicles from a position adjacent the ground or door level to a higher elevation so that access may be gained to the under rigging of the vehicles for the purposes of inspection, repair to and lubrication. i

Among the objects of the invention are to provide a power lift of the class above referred to that is very substantial and durable and is thorou hly reliable; that is compact it and capable oi being installed in a relatively small space, either indoors or out; that may be operated by hydraulic means, pneumatic means, or a combination of both; that may be easily and accurately controlled at all to times by the operator; that is especially convenient ot manipulation, and that is thoroughly sale.

it more specific object of the invention is to provide a power lift of the above mentioned 5315 and a ram operating within said cylinder and ,operatively connected to the vehicle support, and wherein the movements of the ram are controlled by a suitable liquid that is impelled, during the lifting operation, by pressure fluid, such as compressed air, the ram being hollow and serving as a reservoir for the liquid, thus making the apparatus self-contained and avoidinm the necessity of includ- 35 ring a separate tan for the storage of the liquid.

The objects above enumerated, with others that will appear as this description 'roceeds, are attained in the embodiment of t e invention illustrated in the accompanying drawings wherein Fig. l is a side elevation of my improved lift, in elevated position, with a vehicle supported thereon; Fig. 2 is a plan "view cit the apparatus; Fig. 3 is an enlarged lb central vertical section through the cylinder character comprising, generally, a cylinder,

Describing the invention by the use of reference characters, 1 designates a power cyl-,

inder that is preferably set within a cement foundatmn 2 below the ground or floor level that is indicated at 3; A flange 4 is screwed.

or otherwise secured to the top of the cylinder and rests upon the bottom of a pit 5 thatis formed in the concrete foundation 2. J Studs 6 rise from the flange 4 through apertures in a circumferential extension 7 of a guide sleeve 8 that fits within the upper end of the cylinder 1, a gasket 9 being compressed between the circumferential extension 7 of said sleeve and the flange 4 to eflect a leak-proof joint between the cylinder 1 and the guide sleeve 8. The upper end of the guide sleeve is counterbored for the reception of a packing gland 10 between whose lower end and the bottom of the counter-bore is compressed packring having recesses 17 on its underside for a the accommodation of the lower ends of the tie rods 15 and the nuts 18that are applied thereto. Tubular spacers 19 are appliedto the tie rods 15 for positioning the stop 16 a proper distance below the guide'sleeve 8. The guide sleeve and stop, with the tie rods and spacers, are assembled before being insorted into the cylinder 1, and the parts are so proportioned that when inserted the nuts 18 lie so close to the wall of the cylinder 1 that the nuts are prevented from unscrewing bycontact with said well.

Guided within the sleeve 8 and the stop 16 is a hollow ram 20 having a bottom wall to its highest position. When the ram is in its lowest position, it is spaced from the bottoni wall of the cylinder 1 as by lugs 24.

The bottom wall of the ram is provided with an opening or port 25 that is adapted to be closed by a valve 26 on the lower end of a stem 27 that rises through said opening and through the ram and carries a piston 28 adjacent its upper end that operates within a sleeve 29 extending through and shown asformed integral with the top wall 22. Above the piston 28 the stem 27 has connection, through a clevis 30, with a lever 31 that is pivotally connected at 32 to one side of the ram adjacent its upper end. A filling tube 35 also extends through and is shown as formed integral with the top wall 22, and removably applied to the top of the tube 35 is a cap 36. As a convenient means of supplying pressure fluid to the interior of the ram, the cap 36 incorporates a pipe connection that receives the inner end of a nipple 37 which is adapted to be connected by a union 38 to a pressure fluid line 39 that extends outwardly to one side of the apparatus where it is equipped with a three-way valve 40 to the inlet branch of which is coupled a flexible conduit or hose 42 that leads from a compressed air supply (not shown). By means of a handle 43, the valve may be adjusted to establish communication between the conduit or hose 42 and the ressure fluid supply line 39; to interrupt suc communication and prevent the escape of pressure fluid from said line, and to establishv communication betweensaid line and the exhaust 44 of the valve.

Applied to the top of the ram 20, and secured thereto as by means of a set screw 45, isa unit 46 from which I-beams 48 radiate that carry at their outer ends upwardly facing channels that constitute the rails 49 of the vehicle supporting track. These rails are preferably inclined downwardly in both directions from their longitudinal centers, so that a vehicle when run to a substantially central position upon the track is approximately balanced thereon.

The previously mentioned lever 31 extends outwardly through a slot in the cylindrical wall of the ram 20 above the wall 22 thereof and through a registering slot in the unit 46 alongside one of the beams 48 where its outer end islocated in a convenient position to be grasped by an operator standing alongside the structure. The lever 31 is adapted to be latched in its raised and lowered positions within notches '51 and 52 that are formed in a plate 53 applied to the adjacent side of the I'-beam along which the lever extends.

In the use of the apparatus, and assuming that the ram is in retracted position as illustrated in Fig. 3 with the vehicle support adjacent' the ground, and that a quantity of suitable liquid, such as oil, is present in the cylinder 1 about the ram 20 and in the ram to about the level indicated at a, a vehicle may be run onto the track comprising the rails 49 and the brakes set, or if desired, it may be held in position thereon by placing chocks (not shown) against the wheels. The operator then turns the handle 43 of the valve 40 to a position to establish communication between the compressed air conduit or hose 42 and the supply line 39 through which air is directed into the ram by way of the filling tube 35. The pressure of the fluid is now imposed upon the body of oil within the ram 20, and at the same time,upon the underside of the piston 29, and inasmuch as the surface area of said underside of the piston is much greater than that of the valve 26 upon which is imposed the weight of the oil and air pressure, the valve 26 is held closed. The valve 26 may be readily unseated, however, by depressing the outer end of-the lever 31 which action is transmitted to the valve through the connections above described. This opening of the valve allows the liquid in the ram, under the influence of the incoming pressure fluid, to pass through the port 25 and into the cylinder 1, causing it to lift the-ram, together with the vehicle support and the vehicle sustained thereby. When the vehicle has attained the desired elevation, the operator lifts the outer end of the lever 31, thereby to reseat the valve '26 whereupon the passage of oil from the ram to the cylinder ceases and movement of the ram is stopped. The valve 26 is now held sition. The operator may now, or at any timeafter the closing of the valve 26, adjust the valve 40 to establish communication be tween the exhaust thereof,. and the air line 39. This, however, will not result in any movement of the ram inasmuch as it is being supported by the liquid trapped within the cylinder 1. When it is desired to lower the vehicle, the operator disengages the lever 31 from the notch 51 and depresses it, thereby to unseat the valve 26 and permit the liquid to escape from the cylinder into the ram, the air within the ram escaping through the filling tube 35, line 39 and the exhaust 44 of valve 40.

Having thus described our invention, what we claim is:

1. In a power lift of the character described, the combination of a cylinder, a hollow ram operating within the cylinder, the ram having an opening through which its interior is adapted to communicate with the cylinder, the ram containing a quantity of till all

till

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liquid, a valve for controlling the passage of liquid through said opening, manually controlled means for operating the valve, means for introducing fluid under pressure into the ram, means exposed to the fluid pressure in the ram tending to maintain the aforesaid valve closed, and a load support operatively connected to the ram.

2. In a power liftof the character described, the combination of a cylinder, at hollow ram operating within the cylinder and having an opening through which its interior is adapted to communicate with the cylinder, a valve for controlling the passage of fluid through said opening, means exposed to fluid pressure in the ram tending to maintain said valve closed, means for opening and closing the valve, means for creating a fluidpressure condition in the ram, and a load support operatively connected to the ram.

3. In a power lift of the character described, the combination of a cylinder, a hollow ram operating within the cylinder, the ram having'an opening through which its interior is adapted to communicate with the cylinder, a valve for controlling the passage oil fluid through said opening, a stem connected to said valve, means for reciprocating the stem thereby to open and close the valve, means operatively connected to the stem and subjected to pressure in the ram and tending, under the influence of such pressure, to maintain the valve-closed, means for creating a pressure fluid condition in the ram, and a load support operatively connected to the ram.

ln a power lift of the character de-' scribed, the combination of a cylinder, ahollow ram operating within saidcylinder and having top and bottom walls, an opening in said bottom wall through which the interior ot the ram is adapted to communicate with the cylinder, a sleeve in the top wall of the ram that is substantially in axial alignment with said opening in the bottom wall, a valve below the bottom wall of the ram for closing said opening, a stem rising from said valve through said opening and through the sleeve of the top wall, a piston on said stem operating within said sleeve, means. operatively connected with the upppr end of the stem tor reciprocating it there y to open and close the valve, means for creating a pressure fluid condition in the ram, and a load support operatively connected to the, ram.

5. ln a power lift of the character described, the combination of a cylinder, a hollow ram operating within the cylinder and having top and bottom walls, an opening in said bottom wall through which the interior the cylinder, a sleeve in the top Wall that is substantially in axial alignment with said opening, a valve below the bottom wall of M the ram for closing said opening, a stem rising from said valve through said opening and ot the ram is adapted to communicate with through the sleeveofthe top wall, a piston on said stem operating within said sleeve, a

' lever pivotally supported above the top wall of the ram, connections between the lever and said stem whereby the stem may be reciprocated and the valve opened and closed by a swinging of the said lever, means for creating a ressure fluid condition in the ram, and a loa support operatively connected to the ram.

6. In a power lift of the character described, the combination of a cylinder, a hollow ram operating within said cylinder and having top and bottom walls, an opening in said bottom wall through which the interior of the ram is adapted to communicate with the cylinder, a sleeve in the top wall of the ram that is substantially in axial alignment with said opening, a valve below the bottom wall for closing said opening, a stem rising from said valve through said opening and through the sleeve of the top wall, a piston on said stem operatingwithin said sleeve, a lever pivotally supported above the top wall of the ram, connections between the lever and said stem whereby the stem may be reciprocated and the Valve opened and,closed by a swinging of said lever between two posif tions, means for retaining the lever in either of said position, means for creating fluid pressure in the ram, and a load support operatively connected to the ram.

7. In a power lift of the character described, the combination of a'cylinder, a guide sleeve within the top of the cylinder, tie rods depending therefrom, an annular stop applied to the lower ends of the ties rods and through which said tie rods extend, nuts threaded on the lower ends of the tie rods and held againstunscrewing by contact with J the cylinder wall, the underside of the stop being notched for the accommodation of said nuts and the lower ends of the rods, a ram operating within the-cylinder and guided by said sleeve, the ram having an extension for cooperation with the stop, means for creating acpressure fluid condition in the ram, and a loa support operatively connected to the ram. 8. In a power lift of the character described, the combination of a cylinder, a guide sleeve within the top'of'the cylinder, tie rods depending therefrom, spacers on the tie rods, an annular stop secured to the lower ends of said rods in contact with the spacers, a ram I an annular stop supported within the cylinder by said tie rods a suitable distance below the guide sleeve, a cylindrical ram operatmg within the cylinder and guided by said sleeve and having. a projection adjacent its lower end for engagement with the stop, a packing gland for efiecting a fluid tight joint between the ram and said guide sleeve, means for creating a pressure fluid condition in the cylinder, and aload support operatively' connected to the ram;

' In testimony whereof, we hereunto aflix our signatures. I a

FRANCIS W. PERRY.

EDWIN WIEGAND. 

